1/* 2 * WMA compatible codec 3 * Copyright (c) 2002-2007 The Libav Project 4 * 5 * This file is part of Libav. 6 * 7 * Libav is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * Libav is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with Libav; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "avcodec.h" 23#include "sinewin.h" 24#include "wma.h" 25#include "wmadata.h" 26 27#undef NDEBUG 28#include <assert.h> 29 30/* XXX: use same run/length optimization as mpeg decoders */ 31//FIXME maybe split decode / encode or pass flag 32static void init_coef_vlc(VLC *vlc, uint16_t **prun_table, 33 float **plevel_table, uint16_t **pint_table, 34 const CoefVLCTable *vlc_table) 35{ 36 int n = vlc_table->n; 37 const uint8_t *table_bits = vlc_table->huffbits; 38 const uint32_t *table_codes = vlc_table->huffcodes; 39 const uint16_t *levels_table = vlc_table->levels; 40 uint16_t *run_table, *level_table, *int_table; 41 float *flevel_table; 42 int i, l, j, k, level; 43 44 init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0); 45 46 run_table = av_malloc(n * sizeof(uint16_t)); 47 level_table = av_malloc(n * sizeof(uint16_t)); 48 flevel_table= av_malloc(n * sizeof(*flevel_table)); 49 int_table = av_malloc(n * sizeof(uint16_t)); 50 i = 2; 51 level = 1; 52 k = 0; 53 while (i < n) { 54 int_table[k] = i; 55 l = levels_table[k++]; 56 for (j = 0; j < l; j++) { 57 run_table[i] = j; 58 level_table[i] = level; 59 flevel_table[i]= level; 60 i++; 61 } 62 level++; 63 } 64 *prun_table = run_table; 65 *plevel_table = flevel_table; 66 *pint_table = int_table; 67 av_free(level_table); 68} 69 70/** 71 *@brief Get the samples per frame for this stream. 72 *@param sample_rate output sample_rate 73 *@param version wma version 74 *@param decode_flags codec compression features 75 *@return log2 of the number of output samples per frame 76 */ 77int av_cold ff_wma_get_frame_len_bits(int sample_rate, int version, 78 unsigned int decode_flags) 79{ 80 81 int frame_len_bits; 82 83 if (sample_rate <= 16000) { 84 frame_len_bits = 9; 85 } else if (sample_rate <= 22050 || 86 (sample_rate <= 32000 && version == 1)) { 87 frame_len_bits = 10; 88 } else if (sample_rate <= 48000 || version < 3) { 89 frame_len_bits = 11; 90 } else if (sample_rate <= 96000) { 91 frame_len_bits = 12; 92 } else { 93 frame_len_bits = 13; 94 } 95 96 if (version == 3) { 97 int tmp = decode_flags & 0x6; 98 if (tmp == 0x2) { 99 ++frame_len_bits; 100 } else if (tmp == 0x4) { 101 --frame_len_bits; 102 } else if (tmp == 0x6) { 103 frame_len_bits -= 2; 104 } 105 } 106 107 return frame_len_bits; 108} 109 110int ff_wma_init(AVCodecContext *avctx, int flags2) 111{ 112 WMACodecContext *s = avctx->priv_data; 113 int i; 114 float bps1, high_freq; 115 volatile float bps; 116 int sample_rate1; 117 int coef_vlc_table; 118 119 if ( avctx->sample_rate <= 0 || avctx->sample_rate > 50000 120 || avctx->channels <= 0 || avctx->channels > 8 121 || avctx->bit_rate <= 0) 122 return -1; 123 124 s->sample_rate = avctx->sample_rate; 125 s->nb_channels = avctx->channels; 126 s->bit_rate = avctx->bit_rate; 127 s->block_align = avctx->block_align; 128 129 dsputil_init(&s->dsp, avctx); 130 ff_fmt_convert_init(&s->fmt_conv, avctx); 131 132 if (avctx->codec->id == CODEC_ID_WMAV1) { 133 s->version = 1; 134 } else { 135 s->version = 2; 136 } 137 138 /* compute MDCT block size */ 139 s->frame_len_bits = ff_wma_get_frame_len_bits(s->sample_rate, s->version, 0); 140 s->next_block_len_bits = s->frame_len_bits; 141 s->prev_block_len_bits = s->frame_len_bits; 142 s->block_len_bits = s->frame_len_bits; 143 144 s->frame_len = 1 << s->frame_len_bits; 145 if (s->use_variable_block_len) { 146 int nb_max, nb; 147 nb = ((flags2 >> 3) & 3) + 1; 148 if ((s->bit_rate / s->nb_channels) >= 32000) 149 nb += 2; 150 nb_max = s->frame_len_bits - BLOCK_MIN_BITS; 151 if (nb > nb_max) 152 nb = nb_max; 153 s->nb_block_sizes = nb + 1; 154 } else { 155 s->nb_block_sizes = 1; 156 } 157 158 /* init rate dependent parameters */ 159 s->use_noise_coding = 1; 160 high_freq = s->sample_rate * 0.5; 161 162 /* if version 2, then the rates are normalized */ 163 sample_rate1 = s->sample_rate; 164 if (s->version == 2) { 165 if (sample_rate1 >= 44100) { 166 sample_rate1 = 44100; 167 } else if (sample_rate1 >= 22050) { 168 sample_rate1 = 22050; 169 } else if (sample_rate1 >= 16000) { 170 sample_rate1 = 16000; 171 } else if (sample_rate1 >= 11025) { 172 sample_rate1 = 11025; 173 } else if (sample_rate1 >= 8000) { 174 sample_rate1 = 8000; 175 } 176 } 177 178 bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate); 179 s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2; 180 181 /* compute high frequency value and choose if noise coding should 182 be activated */ 183 bps1 = bps; 184 if (s->nb_channels == 2) 185 bps1 = bps * 1.6; 186 if (sample_rate1 == 44100) { 187 if (bps1 >= 0.61) { 188 s->use_noise_coding = 0; 189 } else { 190 high_freq = high_freq * 0.4; 191 } 192 } else if (sample_rate1 == 22050) { 193 if (bps1 >= 1.16) { 194 s->use_noise_coding = 0; 195 } else if (bps1 >= 0.72) { 196 high_freq = high_freq * 0.7; 197 } else { 198 high_freq = high_freq * 0.6; 199 } 200 } else if (sample_rate1 == 16000) { 201 if (bps > 0.5) { 202 high_freq = high_freq * 0.5; 203 } else { 204 high_freq = high_freq * 0.3; 205 } 206 } else if (sample_rate1 == 11025) { 207 high_freq = high_freq * 0.7; 208 } else if (sample_rate1 == 8000) { 209 if (bps <= 0.625) { 210 high_freq = high_freq * 0.5; 211 } else if (bps > 0.75) { 212 s->use_noise_coding = 0; 213 } else { 214 high_freq = high_freq * 0.65; 215 } 216 } else { 217 if (bps >= 0.8) { 218 high_freq = high_freq * 0.75; 219 } else if (bps >= 0.6) { 220 high_freq = high_freq * 0.6; 221 } else { 222 high_freq = high_freq * 0.5; 223 } 224 } 225 av_dlog(s->avctx, "flags2=0x%x\n", flags2); 226 av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n", 227 s->version, s->nb_channels, s->sample_rate, s->bit_rate, 228 s->block_align); 229 av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n", 230 bps, bps1, high_freq, s->byte_offset_bits); 231 av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n", 232 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes); 233 234 /* compute the scale factor band sizes for each MDCT block size */ 235 { 236 int a, b, pos, lpos, k, block_len, i, j, n; 237 const uint8_t *table; 238 239 if (s->version == 1) { 240 s->coefs_start = 3; 241 } else { 242 s->coefs_start = 0; 243 } 244 for (k = 0; k < s->nb_block_sizes; k++) { 245 block_len = s->frame_len >> k; 246 247 if (s->version == 1) { 248 lpos = 0; 249 for (i = 0; i < 25; i++) { 250 a = ff_wma_critical_freqs[i]; 251 b = s->sample_rate; 252 pos = ((block_len * 2 * a) + (b >> 1)) / b; 253 if (pos > block_len) 254 pos = block_len; 255 s->exponent_bands[0][i] = pos - lpos; 256 if (pos >= block_len) { 257 i++; 258 break; 259 } 260 lpos = pos; 261 } 262 s->exponent_sizes[0] = i; 263 } else { 264 /* hardcoded tables */ 265 table = NULL; 266 a = s->frame_len_bits - BLOCK_MIN_BITS - k; 267 if (a < 3) { 268 if (s->sample_rate >= 44100) { 269 table = exponent_band_44100[a]; 270 } else if (s->sample_rate >= 32000) { 271 table = exponent_band_32000[a]; 272 } else if (s->sample_rate >= 22050) { 273 table = exponent_band_22050[a]; 274 } 275 } 276 if (table) { 277 n = *table++; 278 for (i = 0; i < n; i++) 279 s->exponent_bands[k][i] = table[i]; 280 s->exponent_sizes[k] = n; 281 } else { 282 j = 0; 283 lpos = 0; 284 for (i = 0; i < 25; i++) { 285 a = ff_wma_critical_freqs[i]; 286 b = s->sample_rate; 287 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b); 288 pos <<= 2; 289 if (pos > block_len) 290 pos = block_len; 291 if (pos > lpos) 292 s->exponent_bands[k][j++] = pos - lpos; 293 if (pos >= block_len) 294 break; 295 lpos = pos; 296 } 297 s->exponent_sizes[k] = j; 298 } 299 } 300 301 /* max number of coefs */ 302 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k; 303 /* high freq computation */ 304 s->high_band_start[k] = (int)((block_len * 2 * high_freq) / 305 s->sample_rate + 0.5); 306 n = s->exponent_sizes[k]; 307 j = 0; 308 pos = 0; 309 for (i = 0; i < n; i++) { 310 int start, end; 311 start = pos; 312 pos += s->exponent_bands[k][i]; 313 end = pos; 314 if (start < s->high_band_start[k]) 315 start = s->high_band_start[k]; 316 if (end > s->coefs_end[k]) 317 end = s->coefs_end[k]; 318 if (end > start) 319 s->exponent_high_bands[k][j++] = end - start; 320 } 321 s->exponent_high_sizes[k] = j; 322#if 0 323 tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ", 324 s->frame_len >> k, 325 s->coefs_end[k], 326 s->high_band_start[k], 327 s->exponent_high_sizes[k]); 328 for (j = 0; j < s->exponent_high_sizes[k]; j++) 329 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]); 330 tprintf(s->avctx, "\n"); 331#endif 332 } 333 } 334 335#ifdef TRACE 336 { 337 int i, j; 338 for (i = 0; i < s->nb_block_sizes; i++) { 339 tprintf(s->avctx, "%5d: n=%2d:", 340 s->frame_len >> i, 341 s->exponent_sizes[i]); 342 for (j = 0; j < s->exponent_sizes[i]; j++) 343 tprintf(s->avctx, " %d", s->exponent_bands[i][j]); 344 tprintf(s->avctx, "\n"); 345 } 346 } 347#endif 348 349 /* init MDCT windows : simple sinus window */ 350 for (i = 0; i < s->nb_block_sizes; i++) { 351 ff_init_ff_sine_windows(s->frame_len_bits - i); 352 s->windows[i] = ff_sine_windows[s->frame_len_bits - i]; 353 } 354 355 s->reset_block_lengths = 1; 356 357 if (s->use_noise_coding) { 358 359 /* init the noise generator */ 360 if (s->use_exp_vlc) { 361 s->noise_mult = 0.02; 362 } else { 363 s->noise_mult = 0.04; 364 } 365 366#ifdef TRACE 367 for (i = 0; i < NOISE_TAB_SIZE; i++) 368 s->noise_table[i] = 1.0 * s->noise_mult; 369#else 370 { 371 unsigned int seed; 372 float norm; 373 seed = 1; 374 norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult; 375 for (i = 0; i < NOISE_TAB_SIZE; i++) { 376 seed = seed * 314159 + 1; 377 s->noise_table[i] = (float)((int)seed) * norm; 378 } 379 } 380#endif 381 } 382 383 /* choose the VLC tables for the coefficients */ 384 coef_vlc_table = 2; 385 if (s->sample_rate >= 32000) { 386 if (bps1 < 0.72) { 387 coef_vlc_table = 0; 388 } else if (bps1 < 1.16) { 389 coef_vlc_table = 1; 390 } 391 } 392 s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2 ]; 393 s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1]; 394 init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0], 395 s->coef_vlcs[0]); 396 init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1], 397 s->coef_vlcs[1]); 398 399 return 0; 400} 401 402int ff_wma_total_gain_to_bits(int total_gain) 403{ 404 if (total_gain < 15) return 13; 405 else if (total_gain < 32) return 12; 406 else if (total_gain < 40) return 11; 407 else if (total_gain < 45) return 10; 408 else return 9; 409} 410 411int ff_wma_end(AVCodecContext *avctx) 412{ 413 WMACodecContext *s = avctx->priv_data; 414 int i; 415 416 for (i = 0; i < s->nb_block_sizes; i++) 417 ff_mdct_end(&s->mdct_ctx[i]); 418 419 if (s->use_exp_vlc) { 420 ff_free_vlc(&s->exp_vlc); 421 } 422 if (s->use_noise_coding) { 423 ff_free_vlc(&s->hgain_vlc); 424 } 425 for (i = 0; i < 2; i++) { 426 ff_free_vlc(&s->coef_vlc[i]); 427 av_free(s->run_table[i]); 428 av_free(s->level_table[i]); 429 av_free(s->int_table[i]); 430 } 431 432 return 0; 433} 434 435/** 436 * Decode an uncompressed coefficient. 437 * @param gb GetBitContext 438 * @return the decoded coefficient 439 */ 440unsigned int ff_wma_get_large_val(GetBitContext* gb) 441{ 442 /** consumes up to 34 bits */ 443 int n_bits = 8; 444 /** decode length */ 445 if (get_bits1(gb)) { 446 n_bits += 8; 447 if (get_bits1(gb)) { 448 n_bits += 8; 449 if (get_bits1(gb)) { 450 n_bits += 7; 451 } 452 } 453 } 454 return get_bits_long(gb, n_bits); 455} 456 457/** 458 * Decode run level compressed coefficients. 459 * @param avctx codec context 460 * @param gb bitstream reader context 461 * @param vlc vlc table for get_vlc2 462 * @param level_table level codes 463 * @param run_table run codes 464 * @param version 0 for wma1,2 1 for wmapro 465 * @param ptr output buffer 466 * @param offset offset in the output buffer 467 * @param num_coefs number of input coefficents 468 * @param block_len input buffer length (2^n) 469 * @param frame_len_bits number of bits for escaped run codes 470 * @param coef_nb_bits number of bits for escaped level codes 471 * @return 0 on success, -1 otherwise 472 */ 473int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb, 474 VLC *vlc, 475 const float *level_table, const uint16_t *run_table, 476 int version, WMACoef *ptr, int offset, 477 int num_coefs, int block_len, int frame_len_bits, 478 int coef_nb_bits) 479{ 480 int code, level, sign; 481 const uint32_t *ilvl = (const uint32_t*)level_table; 482 uint32_t *iptr = (uint32_t*)ptr; 483 const unsigned int coef_mask = block_len - 1; 484 for (; offset < num_coefs; offset++) { 485 code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX); 486 if (code > 1) { 487 /** normal code */ 488 offset += run_table[code]; 489 sign = get_bits1(gb) - 1; 490 iptr[offset & coef_mask] = ilvl[code] ^ sign<<31; 491 } else if (code == 1) { 492 /** EOB */ 493 break; 494 } else { 495 /** escape */ 496 if (!version) { 497 level = get_bits(gb, coef_nb_bits); 498 /** NOTE: this is rather suboptimal. reading 499 block_len_bits would be better */ 500 offset += get_bits(gb, frame_len_bits); 501 } else { 502 level = ff_wma_get_large_val(gb); 503 /** escape decode */ 504 if (get_bits1(gb)) { 505 if (get_bits1(gb)) { 506 if (get_bits1(gb)) { 507 av_log(avctx,AV_LOG_ERROR, 508 "broken escape sequence\n"); 509 return -1; 510 } else 511 offset += get_bits(gb, frame_len_bits) + 4; 512 } else 513 offset += get_bits(gb, 2) + 1; 514 } 515 } 516 sign = get_bits1(gb) - 1; 517 ptr[offset & coef_mask] = (level^sign) - sign; 518 } 519 } 520 /** NOTE: EOB can be omitted */ 521 if (offset > num_coefs) { 522 av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n"); 523 return -1; 524 } 525 526 return 0; 527} 528 529